/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.util;

import org.apache.catalina.Context;

import javax.servlet.SessionCookieConfig;

public class SessionConfig {

	private static final String DEFAULT_SESSION_COOKIE_NAME = "JSESSIONID";
	private static final String DEFAULT_SESSION_PARAMETER_NAME = "jsessionid";

	private SessionConfig() {
		// Utility class. Hide default constructor.
	}

	/**
	 * Determine the name to use for the session cookie for the provided
	 * context.
	 *
	 * @param context
	 */
	public static String getSessionCookieName(Context context) {

		String result = getConfiguredSessionCookieName(context);

		if (result == null) {
			result = DEFAULT_SESSION_COOKIE_NAME;
		}

		return result;
	}

	/**
	 * Determine the name to use for the session cookie for the provided
	 * context.
	 *
	 * @param context
	 */
	public static String getSessionUriParamName(Context context) {

		String result = getConfiguredSessionCookieName(context);

		if (result == null) {
			result = DEFAULT_SESSION_PARAMETER_NAME;
		}

		return result;
	}

	private static String getConfiguredSessionCookieName(Context context) {

		// Priority is:
		// 1. Cookie name defined in context
		// 2. Cookie name configured for app
		// 3. Default defined by spec
		if (context != null) {
			String cookieName = context.getSessionCookieName();
			if (cookieName != null && cookieName.length() > 0) {
				return cookieName;
			}

			SessionCookieConfig scc =
					context.getServletContext().getSessionCookieConfig();
			cookieName = scc.getName();
			if (cookieName != null && cookieName.length() > 0) {
				return cookieName;
			}
		}

		return null;
	}
}
